The invention relates to a process for the production of layers of a chemical compound, in particular compound semiconductors, on a substrate by means of epitaxy.
According to the state of the art, epitaxial layers, in particular of compound semiconductors, are produced either with metal-organic vapor-phase epitaxy (MOVPE) or molecular beam epitaxy (MBE). With both processes, the compound semiconductor is produced on the hot substrate, on which the deposition of the epitaxial layer takes place. In the case of the metal-organic vapor phase epitaxy the compound semiconductor is formed from suitable vaporous precursor substances which are thermally degraded on the hot substrate, or, in the case of the molecular beam epitaxy, the compound semiconductor is formed from elementary components on the hot substrate.
Particularly with the epitaxial growth of nitride group III compound semiconductors, such as AlN, GaN, InN, difficulties occur, due to the strong bonding of nitrogen compounds, during the required degradation of these compounds on the hot substrate. This leads to unfavorable stoichiometric ratios in the semiconductor layer which has been deposited epitaxially, for example to nitrogen deficiencies, and therefore to poor layer qualities.